Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. Cispĭus, a, um, a Roman gentile name; e. g. M. Cispius, Cic. post Red. in Sen. 8, 21; id. Planc. 31, 75 al.
2. Cispĭus (also Cespĭus, old form in Varr. L. L. 5, § 50 Müll.): mons, one of the peaks of the Mons Esquilinus, now the church S. Maria Maggiore, Varr. L. L. l. l.; Gell. 15, 1, 2; Fest. p. 348, 28; p. 351, 1; Paul. ex Fest. p. 42, 11; cf. Becker, Antiq. 1, p. 534 sq.